And Moses went into the midst of the cloud, and gat him up into the mount: and Moses was in the mount forty days and forty nights. (24:18)

And he was there with the Lord forty days and forty nights; he did neither eat bread, nor drink water. And he wrote upon the tables the words of the covenant, the ten commandments. (34:28)

--Deuteronomy--

When I was gone up into the mount to receive the tables of stone, [even] the tables of the covenant which the Lord made with you, then I abode in the mount forty days and forty nights, I neither did eat bread nor drink water: (9:9)

And I fell down before the Lord, as at the first, forty days and forty nights: I did neither eat bread, nor drink water, because of all your sins which ye sinned, in doing wickedly in the sight of the Lord, to provoke him to anger. (9:18)